#define CONTROL_HTML \
    "\
<head><meta charset='utf-8'></head>\
<script>var xhttp = new XMLHttpRequest();\
    function controlSolve(code){\
        xhttp.open('GET', './control_solve?ctrl_code='+code, true);\
        xhttp.send();\
    }\
</script>\
<center>\
    这个页面将用于车车的简单控制</br>\
    </br>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"on\")'>on</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"forward\")'>▲</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"more\")'>+</button></br>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"left\")'>◀</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"stop\")'>◆</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"right\")'>▶</button></br>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"off\")'>off</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"backward\")'>▼</button>\
    <button style='width:200px; height:200px; margin: 10px; font-size: 100px;' onclick='controlSolve(\"less\")'>-</button></br>\
</center>\
"
// END =====================================================
